DOCSLIB.ORG

Fossil Lagerstätte from Ya Ha Tinda, Alberta, Canada

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Fossil Lagerstätte from Ya Ha Tinda, Alberta, Canada A new Early Jurassic (ca. 183 Ma) fossil Lagerstätte from Ya Ha Tinda, Alberta, Canada Rowan C. Martindale1,2*, Theodore R. Them II3,4, Benjamin C. Gill3, Selva M. Marroquín1,3, and Andrew H. Knoll2 1Department of Geological Sciences, The University of Texas at Austin, 1 University Station C1100, Austin, Texas 78712, USA 2Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, Massachusetts 02138, USA 3Department of Geosciences, Virginia Polytechnic Institute and State University, 4044 Derring Hall (0420), Blacksburg, Virginia 24061, USA 4Department of Earth, Ocean and Atmospheric Science & National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA ABSTRACT Figure 1. Global paleoge- Lagerstätten—deposits of exceptionally preserved fossils—offer ography during Toarcian vital insights into evolutionary history. To date, only three Konservat- and location of Ya Ha Tinda Hispanic (Alberta, Canada; yellow Lagerstätten are known from Early Jurassic marine rocks (Osteno, Corridor Tethys star), Strawberry Bank (UK; Posidonia Shale, and Strawberry Bank), all located in Europe. We gray star), and Posidonia report a new assemblage of exceptionally preserved fossils from Panthalassa Shale (Germany; black star) Alberta, Canada, the first marine Konservat-Lagerstätte described Lagerstätten. Green areas are Pangea landmasses, light-blue areas from the Jurassic of North America. The Ya Ha Tinda assemblage are shallow seas, and dark includes articulated vertebrates (fish, ichthyosaurs), crinoids, crus- blue represents open oceans. taceans, brachiopods, abundant mollusks (coleoids with soft tissues, ammonites, gastropods, bivalves), wood, and microfossils. Paired bio- METHODS and chemostratigraphies show that Lagerstätte deposition occurred Exposures of the Fernie Formation at the Ya Ha Tinda Ranch (south- during the late Pliensbachian through early Toarcian, capturing the west Alberta) were measured and described in centimeter-scale detail; carbon isotope excursion associated with the Toarcian Oceanic Anoxic exact localities cannot be disclosed. Intervals with exceptional preserva- Event. Therefore, the Panthalassan Ya Ha Tinda biota is coeval with tion (e.g., Fig. 2) were quarried and specimens prepared for study (repos- Toarcian Lagerstätten from the Tethys Ocean (Posidonia Shale and ited at the Royal Tyrrell Museum of Palaeontology, Canada); see the Strawberry Bank). Comparisons among these deposits permit new GSA Data Repository1 for extraction, preparation, and analytical techniques. insights into the diversity, ecology, and biogeography of Jurassic marine communities during a time of pronounced biological and RESULTS environmental change (e.g., expanded subsurface anoxia, warming, and extinctions). They also highlight the possibility that Mesozoic Ya Ha Tinda Biota Oceanic Anoxic Events are temporal foci of exceptional preservation. At Ya Ha Tinda, exceptionally preserved fossils can be found in both the Red Deer and Poker Chip Shale members of the Fernie Formation (Fig. INTRODUCTION 2). Platy calcareous shales interbedded with fine siltstones and black lime- During the Early Jurassic there were several major environmental and stones compose the late Pliensbachian–early Toarcian Red Deer Member, ecological perturbations that influenced Mesozoic evolution, notably the whereas the Toarcian Poker Chip Shale is composed of poorly cemented, Toarcian Oceanic Anoxic Event (T-OAE). The T-OAE is associated with black calcareous shales and mudstones interbedded locally with bitu- benthic and pelagic extinctions including ammonites, fish, foraminifers, minous limestones (Fig. 2; Them et al., 2017). Ages of these units are radiolarians, corals, bivalves, and brachiopods (e.g., Little and Benton, constrained by ammonite and coccolith biostratigraphy, carbon isotope 1995; Lathuilière and Marchal, 2009; Caruthers et al., 2014; Caswell and chemostratigraphy, and U-Pb zircon dates from intercalated ash beds in Coe, 2014; Danise et al., 2015). Compelling as this record may be, it is outcrops at Ya Ha Tinda Ranch (Hall et al., 2004; Them et al., 2017). Well- biased; unbiomineralized organisms are rarely preserved, yet represent preserved specimens have previously been collected, mostly from float the majority of marine biodiversity (e.g., Schopf, 1978; Morris, 1986). (Hall, 1985, 1991; Feldmann and Copeland, 1988), but the full scope of While unusual environmental circumstances allow for preservation of preservation (i.e., soft tissue preservation at multiple horizons) and fossil soft tissues and provide a more complete perspective on evolutionary abundance has only recently become apparent. The preservation of cuticle history in Konservat-Lagerstätten (Seilacher, 1970; Briggs, 2003), only (arthropod carapaces) and soft tissue (coleoid ink sacs and mantle muscle two occur within the T-OAE: the Posidonia Shale (primarily) in Germany tissue) (Fig. 3) marks this deposit as a Konservat-Lagerstätte. (e.g., Seilacher, 1990) and the British Strawberry Bank Lagerstätte (Wil- Coleoid cephalopods, specifically Vampyropoda (eight-armed, gladius- liams et al., 2015). bearing coleoids), exhibit the most exceptional preservation. Vampyropod Here we describe a new Early Jurassic (Pliensbachian–Toarcian) specimens (Figs. 3D–3E) include isolated gladii (chitinous internal shell), Lagerstätte from Alberta, Canada: the Ya Ha Tinda assemblage (Fig. 1). gladii and ink sacs, and gladii with mantle muscle and ink sacs. Chitinous This deposit is significant as both the first marine Konservat-Lagerstätte described from the Jurassic of North America and the first described 1 GSA Data Repository item 2017066, sample excavation, preparation, and ana- Pliensbachian–Toarcian Lagerstätte outside of Europe. lytical methods, lithological description, and additional fossil images, is available online at www.geosociety.org/datarepository /2017 or on request from editing@ *E-mail: [email protected] geosociety.org. GEOLOGY, March 2017; v. 45; no. 3; p. 255–258 | Data Repository item 2017066 | doi:10.1130/G38808.1 | Published online 9 January 2017 GEOLOGY© 2017 The Authors.| Volume Gold 45 |Open Number Access: 3 | www.gsapubs.orgThis paper is published under the terms of the CC-BY license. 255 Downloaded from http://pubs.geoscienceworld.org/gsa/geology/article-pdf/45/3/255/3550683/255.pdf by guest on 02 October 2021 . ) Legend 13 ) Limestone δ Corg (% VPDB) -31--30 29 -28 -27-26 Poorly cemented calcareous mudstone LithostratStage Zone Zone(Eu (NA)Strat. height Ya Ha Tinda Fossils 22 (m Calcareous mudstone Calcareous siltstone/concretion a 20 Unfossiliferous calcareous siltstone Interbedded limestone with thin shale lanulat bifrons 18 Interbedded shale/limestone Shell Bed Ash Bed (Bentonite) 16 arcian Barite/Gypsum Needles To Vampyropoda body fossil 14 ep Poker Chip Shale Member Lobster body fossil erpentinum T-OAE Shrimp body fossil or appendage anens 12 CIE Crustacean appendage ns Articulated fish fossil te 10 ek Articulated crinoid/Crinoid Ossicle Bone (vertebrae) 8 Bivalve spinatum arlottens n Brachiopod 6 Ammonite/Aptychus Atractites sp. (belemnite-like coleoid) Wood ec 4 Red Deer Member Coprolite Pliensbachia kuna Diplocraterion trace fossil margaritatus 2 Thalassinoides trace fossil Arenicolites trace fossil 0 d e Rhizocorallium trace fossil silt -31--30 29 -28 -27-26 lim mu Rusophycus trace fossil shale Figure 2. Stratigraphic column of East Tributary of Bighorn Creek section (Fernie Formation, Ya Ha Tinda, Alberta, Canada) with fossil occur- rences (Royal Tyrrell Museum of Palaeontology locality L2428). Chemostratigraphic and biostratigraphic data are modified from Them et al. (2017). Lithostrat.—lithostratigraphy; Strat. height—stratigraphic height in section; Zone (Eu)—northwestern Europe ammonite zonation; Zone (NA)—western North America ammonite zonation; ten.—tenuicostatum; org—organic; VPDB—Vienna Peedee belemnite; T-OAE CIE— Toarcian Oceanic Anoxic Event carbon isotope excursion. tissues typically preserve relatively well (Kear et al., 1995); ink sac pres- aptychi. Additional fossils include a dinosaur bone, brachiopods, gastro- ervation is less easily accounted for, but may relate to the abundance of pods, bivalves, wood, and coccolithophores (Hall, 1991; Hall et al., 1998). decay-resistant melanin in this organ (Glass et al., 2012) and clay min- Ya Ha Tinda bivalves are abundant and taxonomically similar to those eral authigenesis. Recent excavations have uncovered fifteen specimens of from Europe (e.g., Röhl et al., 2001). Compressions of transported logs vampyropods (Figs. 2 and 3; mostly loligosepiids and prototeuthids), making have been found, but no crinoids or bivalves have been attached to them. this the largest known deposit of Jurassic vampyropods outside of Europe. Crustacean preservation at Ya Ha Tinda is excellent. Specimens include Paleoenvironment and Preservation compressions of appendages and fully or partially articulated carcasses Soft tissue preservation has been identified at three different Ya Ha Tinda (Figs. 3F–3H). Full lobster carapaces have only been found below the Ranch outcrops, but the best in situ material occurs in beds exposed along T-OAE carbon isotope excursion (CIE), whereas appendages occur a tributary of Bighorn Creek (herein called East Tributary). The Lagerstätte throughout the studied interval. Ya Ha Tinda crustaceans include a shrimp interval (Fig. 2) occurs from the North American kunae ammonite zone (Fig. 3F) as well as lobsters such
Load more

Recommended publications
  • In Pliocene Deposits, Antarctic Continental Margin (ANDRILL 1B Drill Core) Molly F
    University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln ANDRILL Research and Publications Antarctic Drilling Program 2009 Significance of the Trace Fossil Zoophycos in Pliocene Deposits, Antarctic Continental Margin (ANDRILL 1B Drill Core) Molly F. Miller Vanderbilt University, [email protected] Ellen A. Cowan Appalachian State University, [email protected] Simon H. H. Nielsen Florida State University Follow this and additional works at: http://digitalcommons.unl.edu/andrillrespub Part of the Oceanography Commons, and the Paleobiology Commons Miller, Molly F.; Cowan, Ellen A.; and Nielsen, Simon H. H., "Significance of the Trace Fossil Zoophycos in Pliocene Deposits, Antarctic Continental Margin (ANDRILL 1B Drill Core)" (2009). ANDRILL Research and Publications. 61. http://digitalcommons.unl.edu/andrillrespub/61 This Article is brought to you for free and open access by the Antarctic Drilling Program at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in ANDRILL Research and Publications by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Published in Antarctic Science 21(6) (2009), & Antarctic Science Ltd (2009), pp. 609–618; doi: 10.1017/ s0954102009002041 Copyright © 2009 Cambridge University Press Submitted July 25, 2008, accepted February 9, 2009 Significance of the trace fossil Zoophycos in Pliocene deposits, Antarctic continental margin (ANDRILL 1B drill core) Molly F. Miller,1 Ellen A. Cowan,2 and Simon H.H. Nielsen3 1. Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN 37235, USA 2. Department of Geology, Appalachian State University, Boone, NC 28608, USA 3. Antarctic Research Facility, Florida State University, Tallahassee FL 32306-4100, USA Corresponding author — Molly F.
    [Show full text]
  • The Rock and Fossil Record the Rock and Fossil Record the Rock And
    TheThe RockRock andand FossilFossil RecordRecord Earth’s Story and Those Who First Listened . 426 Apply . 427 Internet Connect . 428 When on Earth? . 429 Activity . 430 MathBreak . 434 Internet Connect 432, 435 Looking at Fossils . 436 QuickLab . 438 Internet Connect . 440 Time Marches On . 441 QuickLab . 443 Internet Connect . 445 Chapter Lab . 446 Chapter Review . 449 TEKS/TAKS Practice Tests . 451, 452 Feature Article . 453 Time Stands Still Pre-Reading Questions Sealed in darkness for 49 million years, this beetle still shimmers with the same metallic hues that once helped it hide among ancient plants. This rare fossil 1. How do scientists study was found in Messel, Germany. In the same rock formation, the Earth’s history? scientists have found fossilized crocodiles, bats, birds, and 2. How can you tell the age frogs. A living stag beetle (above) has a similar form and of rocks and fossils? color. Do you think that these two beetles would live in 3. What natural or human similar environments? What do you think Messel, Germany, events have caused mass was like 49 million years ago? In this chapter, you will extinctions in Earth’s learn how scientists answer these kinds of questions. history? 424 Chapter 16 Copyright © by Holt, Rinehart and Winston. All rights reserved. MAKING FOSSILS Procedure 1. You and three or four of your classmates will be given several pieces of modeling clay and a paper sack containing a few small objects. 2. Press each object firmly into a piece of clay. Try to leave an imprint showing as much detail as possible.
    [Show full text]
  • Tectonic Setting of the Lower Fernie Formation
    Tectonic setting of the lower Fernie Formation: insights from subsidence analysis Tannis McCartney*, Department of Geoscience, University of Calgary, Calgary, Alberta, Canada [email protected] and Andrew Leier, Department of Geoscience, University of Calgary, Calgary, Alberta, Canada Introduction In this study, the Fernie Formation in west-central Alberta is informally divided into upper and lower Fernie. The lower Fernie contains the Nordegg, Gordondale, Red Deer, Poker Chip and Rock Creek Members. These are separated from the Upper Fernie shales by many unconformities, simplified here as a single regional unconformity (Figure 1). Figure 1: Simplified stratigraphic column of the Fernie Formation. In this study, the Fernie Formation is divided into the Upper Fernie (shales) and the lower Fernie (Rock Creek, Poker Chip Shale, and Nordegg). The unconformities separating the Upper Fernie from the lower Fernie are here represented as a single, regional unconformity. The Nordegg and Gordondale Members of the Fernie Formation were deposited during the early stages of tectonic loading in the Cordillera to the west. These members, along with the Poker Chip and Rock Creek Members, were studied to look for evidence of this tectonic activity in the sedimentary record. The results give new insights into current understandings of the lower Fernie Formation. Theory and Method Tectonic subsidence measures the tectonically controlled vertical movement of a basin. Calculating the amount of tectonic subsidence the basin has undergone involves accounting for sediment compaction, paleobathymetry, sea-level changes and post-depositional sediment compaction. GeoConvention 2012: Vision 1 In basin analysis, tectonic subsidence plotted on a depth vs. age chart is used to classify the type of basin the sediments were deposited in.
    [Show full text]
  • Coprolites of Deinosuchus and Other Crocodylians from the Upper Cretaceous of Western Georgia, Usa
    Milàn, J., Lucas, S.G., Lockley, M.G. and Spielmann, J.A., eds., 2010, Crocodyle tracks and traces. New Mexico Museum of Natural History and Science, Bulletin 51. 209 COPROLITES OF DEINOSUCHUS AND OTHER CROCODYLIANS FROM THE UPPER CRETACEOUS OF WESTERN GEORGIA, USA SAMANTHA D. HARRELL AND DAVID R. SCHWIMMER Department of Earth and Space Sciences, Columbus State University, Columbus, GA 31907 USA, [email protected] Abstract—Associated with abundant bones, teeth and osteoderms of the giant eusuchian Deinosuchus rugosus are larger concretionary masses of consistent form and composition. It is proposed that these are crocodylian coprolites, and further, based on their size and abundance, that these are coprolites of Deinosuchus. The associated coprolite assemblage also contains additional types that may come from smaller crocodylians, most likely species of the riverine/estuarine genus Borealosuchus, which is represented by bones, osteoderms and teeth in fossil collections from the same site. INTRODUCTION The Upper Cretaceous Blufftown Formation in western Georgia contains a diverse perimarine and marine vertebrate fauna, including many sharks and bony fish (Case and Schwimmer, 1988), mosasaurs, plesio- saurs, turtles (Schwimmer, 1986), dinosaurs (Schwimmer et al., 1993), and of particular interest here, abundant remains of the giant eusuchian crocodylian Deinosuchus rugosus (Schwimmer and Williams, 1996; Schwimmer, 2002). Together with bite traces attributable to Deinosuchus (see Schwimmer, this volume), there are more than 60 coprolites recov- ered from the same formation, including ~30 specimens that appear to be of crocodylian origin. It is proposed here that the larger coprolites are from Deinosuchus, principally because that is the most common large tetrapod in the vertebrate bone assemblage from the same locality, and it is assumed that feces scale to the producer (Chin, 2002).
    [Show full text]
  • Mary Anning of Lyme Regis: 19Th Century Pioneer in British Palaeontology
    Headwaters Volume 26 Article 14 2009 Mary Anning of Lyme Regis: 19th Century Pioneer in British Palaeontology Larry E. Davis College of St. Benedict / St. John's University, [email protected] Follow this and additional works at: https://digitalcommons.csbsju.edu/headwaters Part of the Geology Commons, and the Paleontology Commons Recommended Citation Davis, Larry E. (2009) "Mary Anning of Lyme Regis: 19th Century Pioneer in British Palaeontology," Headwaters: Vol. 26, 96-126. Available at: https://digitalcommons.csbsju.edu/headwaters/vol26/iss1/14 This Article is brought to you for free and open access by DigitalCommons@CSB/SJU. It has been accepted for inclusion in Headwaters by an authorized editor of DigitalCommons@CSB/SJU. For more information, please contact [email protected]. LARRY E. DAVIS Mary Anning of Lyme Regis 19th Century Pioneer in British Palaeontology Ludwig Leichhardt, a 19th century German explorer noted in a letter, “… we had the pleasure of making the acquaintance of the Princess of Palaeontology, Miss Anning. She is a strong, energetic spinster of about 28 years of age, tanned and masculine in expression …” (Aurousseau, 1968). Gideon Mantell, a 19th century British palaeontologist, made a less flattering remark when he wrote in his journal, “… sallied out in quest of Mary An- ning, the geological lioness … we found her in a little dirt shop with hundreds of specimens piled around her in the greatest disorder. She, the presiding Deity, a prim, pedantic vinegar looking female; shred, and rather satirical in her conversation” (Curwin, 1940). Who was Mary Anning, this Princess of Palaeontology and Geological Lioness (Fig.
    [Show full text]
  • CURRICULUM VITAE Ilya V. Buynevich Ilya V
    CURRICULUM VITAE Ilya V. Buynevich Ilya V. Buynevich Department of Earth and Environmental Science Tel: 215-204-3635 College of Science and Technology Fax: 215-204-3496 Temple University [email protected] 313 Beury Hall http://sites.temple.edu/coastal 1901 N. 13th Street Philadelphia, PA 19122, USA Citizenship: USA EDUCATION 2001-2003 Post-Doctoral, Geology Woods Hole Oceanographic Institution 2001 Ph.D, Geology Boston University 1994 B.A., Geology, Magna Cum Laude Boston University 1989-1991 Dipl. Sci. Program, Marine Geology Odessa National University, Ukraine RESEARCH INTERESTS Coastal and marine geology; field and experimental ichnology; zoogeomorphology; event sedimentology and taphonomy; morphodynamics and stratigraphy of coastal barriers; aeolian processes and dunefield evolution; geoarchaeology and geoforensics; applied high-resolution geophysics (focus: georadar). POSITIONS HELD 2015 > Associate Professor, Earth and Environmental Science, Temple University 2009-2015 Assistant Professor, Earth and Environmental Science, Temple University 2008-2012 Adjunct Graduate Professor of Oceanography, University of Rhode Island 2004-2009 Assistant Scientist, Geology & Geophysics, Woods Hole Oceanographic Institution 2000-2009 Part-time Faculty, Metropolitan College, Boston University 2007-2009 Visiting Faculty, Earth and Environmental Science, Boston College 2007-2008 Adjunct Faculty, Marine Geology, Kiev National University, Ukraine 2003-2004 Research Geologist, U.S. Geological Survey, Woods Hole Field Center 2001-2003 USGS Postdoctoral Scholar, Woods Hole Oceanographic Institution (WHOI) 1999, 2009 Visiting Faculty, Geology, Tufts University 1997-2000 Research Assistant, Department of Earth Sciences, Boston University PROFESSIONAL ACTIVITY 2014 > - Editorial Board, Geology Bulletin, Lviv National University, Ukraine Geology and Geography Bulletin, Odessa National University, Ukraine 2013 > - Editorial Board, Baltica 2011 > - Associate Editor, Journal of Coastal Research I.V.
    [Show full text]
  • Teacher's Booklet
    Ideas and Evidence at the Sedgwick Museum of Earth Sciences Teacher’s Booklet Acknowledgements Shawn Peart Secondary Consultant Annette Shelford Sedgwick Museum of Earth Sciences Paul Dainty Great Cornard Upper School Sarah Taylor St. James Middle School David Heap Westley Middle School Thanks also to Dudley Simons for photography and processing of the images of objects and exhibits at the Sedgwick Museum, and to Adrienne Mayor for kindly allowing us to use her mammoth and monster images (see picture credits). Picture Credits Page 8 “Bag of bones” activity adapted from an old resource, source unknown. Page 8 Iguanodon images used in the interpretation of the skeleton picture resource from www.dinohunters.com Page 9 Mammoth skeleton images from ‘The First Fossil Hunters’ by Adrienne Mayor, Princeton University Press ISBN: 0-691-05863 with kind permission of the author Page 9 Both paintings of Mary Anning from the collections of the Natural History Museum © Natural History Museum, London 1 Page 12 Palaeontologists Picture from the photographic archive of the Sedgwick Museum © Sedgwick Museum of Earth Sciences Page 14 Images of Iguanodon from www.dinohunters.com Page 15 “Duria Antiquior - a more ancient Dorsetshire” by Henry de la Beche from the collection of the National Museums and Galleries of Wales © National Museum of Wales Page 17 Images of Deinotherium giganteum skull cast © Sedgwick Museum of Earth Sciences Page 19 Image of red sandstone slab © Sedgwick Museum of Earth Sciences 2 Introduction Ideas and evidence was introduced as an aspect of school science after the review of the National Curriculum in 2000. Until the advent of the National Strategy for Science it was an area that was often not planned for explicitly.
    [Show full text]
  • Making a Trace Fossil
    WSC National Fossil Day 2020@ HOME Making a Trace Fossil Gathering Supplies: Soft Modeling Clay or Homemade Salt Dough Rolling Pen Toothpick Leaves, Sticks, Bark and/or Shells Paint Brushes (Optional) Types of Fossils! There are two main types of fossils that paleontologists study: body fossils and trace fossils. So what is the difference between the two? Body fossils are probably what you think of most when you hear the word fossil. Like the large bones of a dinosaur. Body fossils are fossils that retain or keep the actual remains of an animal, even though it goes through the fossilization process. Think about fossils of a tooth, a claw, or skull of an ancient animal. These are all parts of the actual animal that have become a fossil. So if the original remains of a plant, insect or animal become fossilized, this would be a body fossil. Trace fossils show the activity of a plant or animal, without any of the actual remains being present. Examples of trace fossils are tracks of animals, or signs of their scratching and burrowing. Even fossilized poop is a type of trace fossil. The imprint of a leaf or bark from a tree or the texture of a shell are all examples of trace fossils. Remember a trace fossil will show the presence of an living organism without an actual part of their remains being fossilized. They can give clues to what animals did and how they acted along with what their environment was like. Try This! Making your own trace fossil. Go out on a nature walk with your family, in your neighborhood or in your backyard.
    [Show full text]
  • Trace Fossils and Substrates of the Terminal Proterozoic–Cambrian Transition: Implications for the Record of Early Bilaterians and Sediment Mixing
    Trace fossils and substrates of the terminal Proterozoic–Cambrian transition: Implications for the record of early bilaterians and sediment mixing Mary L. Droser*†,So¨ ren Jensen*, and James G. Gehling‡ *Department of Earth Sciences, University of California, Riverside, CA 92521; and ‡South Australian Museum, Division of Natural Sciences, North Terrace, Adelaide 5000, South Australia, Australia Edited by James W. Valentine, University of California, Berkeley, CA, and approved August 16, 2002 (received for review May 29, 2002) The trace fossil record is important in determining the timing of the appearance of bilaterian animals. A conservative estimate puts this time at Ϸ555 million years ago. The preservational potential of traces made close to the sediment–water interface is crucial to detecting early benthic activity. Our studies on earliest Cambrian sediments suggest that shallow tiers were preserved to a greater extent than typical for most of the Phanerozoic, which can be attributed both directly and indirectly to the low levels of sediment mixing. The low levels of sediment mixing meant that thin event beds were preserved. The shallow depth of sediment mixing also meant that muddy sediments were firm close to the sediment–water interface, increasing the likelihood of recording shallow-tier trace fossils in muddy sed- iments. Overall, trace fossils can provide a sound record of the onset of bilaterian benthic activity. he appearance and subsequent diversification of bilaterian Tanimals is a topic of current controversy (refs. 1–7; Fig. 1). Three principal sources of evidence exist: body fossils, trace fossils (trails, tracks, and burrows of animal activity recorded in the sedimentary record), and divergence times calculated by means of a molecular ‘‘clock.’’ The body fossil record indicates a geologically rapid diversification of bilaterian animals not much earlier than the Precambrian–Cambrian boundary, the so-called Cambrian explosion.
    [Show full text]
  • Innovations in Animal-Substrate Interactions Through Geologic Time
    The other biodiversity record: Innovations in animal-substrate interactions through geologic time Luis A. Buatois, Dept. of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon SK S7N 5E2, Canada, luis. [email protected]; and M. Gabriela Mángano, Dept. of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon SK S7N 5E2, Canada, [email protected] ABSTRACT 1979; Bambach, 1977; Sepkoski, 1978, 1979, and Droser, 2004; Mángano and Buatois, Tracking biodiversity changes based on 1984, 1997). However, this has been marked 2014; Buatois et al., 2016a), rather than on body fossils through geologic time became by controversies regarding the nature of the whole Phanerozoic. In this study we diversity trajectories and their potential one of the main objectives of paleontology tackle this issue based on a systematic and biases (e.g., Sepkoski et al., 1981; Alroy, in the 1980s. Trace fossils represent an alter- global compilation of trace-fossil data 2010; Crampton et al., 2003; Holland, 2010; native record to evaluate secular changes in in the stratigraphic record. We show that Bush and Bambach, 2015). In these studies, diversity. A quantitative ichnologic analysis, quantitative ichnologic analysis indicates diversity has been invariably assessed based based on a comprehensive and global data that the three main marine evolutionary on body fossils. set, has been undertaken in order to evaluate radiations inferred from body fossils, namely Trace fossils represent an alternative temporal trends in diversity of bioturbation the Cambrian Explosion, Great Ordovician record to assess secular changes in bio- and bioerosion structures. The results of this Biodiversification Event, and Mesozoic diversity. Trace-fossil data were given less study indicate that the three main marine Marine Revolution, are also expressed in the attention and were considered briefly in evolutionary radiations (Cambrian Explo- trace-fossil record.
    [Show full text]
  • Structural Geology of the Southern Livingstone Range
    Meteoric fluid isotopic signatures of thrust-fault-related veins in the Livingstone Range anticlinorium and their significance for syn-deformational regional fluid migration Michael A. Cooley*, Raymond A. Price, John M. Dixon, and T. Kurtis Kyser Department of Geological Sciences and Geological Engineering Queen’s University, Kingston, Kingston, ON, K7L 3N6 [email protected] ABSTRACT δ13C and δ18O isotope values of calcite in veins and host rocks from thrust fault zones indicate that fluids with meteoric isotopic signatures were present along thrust faults and infiltrating the tip-lines of minor thrusts during the formation of fault-propagation folds in the Livingstone Range Anticlinorium of southwest Alberta. Isotope geochemistry of cross-fault veins indicates that formation fluids predominated within the transverse structures, implying that cross faults were not conduits for local downward infiltration of meteoric water. Meteoric fluids must have been flowing eastward along the major thrust faults from a recharge area in the topographically higher hinterland to the west during formation of the thrust and fold belt. The incursion of meteoric waters coincided with hydrocarbon migration as indicated by hydrocarbon residues within thrust- fault-related calcite veins. Introduction The Livingstone Range of the southern Alberta foothills comprises the easternmost surface exposures of Carboniferous rocks in the southern Canadian Cordillera (Fig. 1). The Livingstone Range is an anticlinorium that developed where the Livingstone thrust cuts up-section in its hanging wall from a regional detachment in the upper Palliser Formation, through the overlying Mississippian Rundle Group and younger strata to an upper detachment within the Jurassic Fernie Formation. The anticlinorium comprises two to three adjacent fault- propagation fold anticlines which contain thrust faults that die out upwards into the cores of the folds.
    [Show full text]
  • Mary Anning: Princess of Palaeontology and Geological Lioness
    The Compass: Earth Science Journal of Sigma Gamma Epsilon Volume 84 Issue 1 Article 8 1-6-2012 Mary Anning: Princess of Palaeontology and Geological Lioness Larry E. Davis College of St. Benedict / St. John's University, [email protected] Follow this and additional works at: https://digitalcommons.csbsju.edu/compass Part of the Paleontology Commons Recommended Citation Davis, Larry E. (2012) "Mary Anning: Princess of Palaeontology and Geological Lioness," The Compass: Earth Science Journal of Sigma Gamma Epsilon: Vol. 84: Iss. 1, Article 8. Available at: https://digitalcommons.csbsju.edu/compass/vol84/iss1/8 This Article is brought to you for free and open access by DigitalCommons@CSB/SJU. It has been accepted for inclusion in The Compass: Earth Science Journal of Sigma Gamma Epsilon by an authorized editor of DigitalCommons@CSB/SJU. For more information, please contact [email protected]. Figure. 1. Portrait of Mary Anning, in oils, probably painted by William Gray in February, 1842, for exhibition at the Royal Academy, but rejected. The portrait includes the fossil cliffs of Lyme Bay in the background. Mary is pointing at an ammonite, with her companion Tray dutifully curled beside the ammonite protecting the find. The portrait eventually became the property of Joseph, Mary‟s brother, and in 1935, was presented to the Geology Department, British Museum, by Mary‟s great-great niece Annette Anning (1876-1938). The portrait is now in the Earth Sciences Library, British Museum of Natural History. A similar portrait in pastels by B.J.M. Donne, hangs in the entry hall of the Geological Society of London.
    [Show full text]